Optical device housing

ABSTRACT

An apparatus for mitigating contamination of an optical device comprises an open-topped, closed-sided, and closed-bottomed housing cup partially defining a protected volume to enclose the optical device. A housing cap encloses a top of the housing cup and partially defines the protected volume. The housing cap includes a top collar having an open central aperture. The top collar includes at least one drain channel extending longitudinally downward into a top collar top surface and extending across the top collar top surface laterally outward from the central aperture. A top cover laterally spans the central aperture of the top collar. An interface structure circumscribes the top cover to suspend the top cover downwardly into the housing cup from the top collar. The interface structure prevents direct contact between the top cover and the top collar.

RELATED APPLICATION

This application claims priority from U.S. Provisional Application No.62/454,972, filed 6 Feb. 2017 and entitled LENS COVER HOUSING WITH DRAINCHANNEL, the subject matter of which is incorporated herein by referencein its entirety.

This application is related to the following co-owned co-pending U.S.Patent Application: U.S. patent application Ser. No. 15/377,492, filedDec. 13, 2016.

TECHNICAL FIELD

This disclosure relates to an apparatus and method for mitigatingcontamination of an optical device and, more particularly, to a methodand apparatus for use of an optical device housing.

BACKGROUND

For use environments such as vehicle backup cameras, it may be desirableto enclose an optical device in a housing to protect the optical devicefrom contaminants including fluids, particles, and other unwantedmatter. However, the optical device should still be in visual contactwith the ambient space outside the housing for many such useenvironments. The optical devices are often too small to warrant theexpense and inconvenience of a transversely-wiping squeegee or othermechanically contacting clearance devices. As a result, an ultrasonictransducer may be provided to longitudinally and/or laterally vibrate atransparent cover portion of the housing along an axis of the lens. Thecover vibration occurs at very high frequencies, and acts to break upliquid surface tension, overcome adhesion due to electrostatic and/orVan der Waals forces, and otherwise shake contaminants away from theouter cover surface. However, this ultrasonic vibration can be damagingto various portions of the housing and the enclosed optical device (orcomponents associated therewith), due to unwanted ultrasonic weldingeffects and/or mechanical wear.

SUMMARY

As one example, an apparatus for mitigating contamination of an opticaldevice is described. The apparatus comprises an open-topped,closed-sided, and closed-bottomed housing cup partially defining aprotected volume to enclose the optical device. A housing cap encloses atop of the housing cup and partially defines the protected volume. Thehousing cap includes a top collar having an open central aperture. Thetop collar includes at least one drain channel extending longitudinallyinto a top collar top surface and extending at least partially acrossthe top collar top surface laterally outward from the central aperture.A top cover laterally spans the central aperture of the top collar. Aninterface structure circumscribes the top cover to suspend the top coverinto the housing cup from the top collar. The interface structureprevents direct contact between the top cover and the top collar.

As another example, an optical device housing is described. A sidewallhas longitudinally spaced top and bottom sidewall rims. The sidewallencloses a lateral dimension of a protected volume. A bottom platelaterally spans the bottom sidewall rim to enclose a bottom side andlower longitudinal dimension of the protected volume. A housing capincludes a top cover laterally spanning a portion of the top sidewallrim to partially enclose a top side and upper longitudinal dimension ofthe protected volume. The top cover is laterally separated from the topsidewall rim by an insulation gap. A top collar laterally surrounds thetop sidewall rim. The top collar laterally spans the insulation gap tocomplete longitudinal enclosure of the top side of the protected volume.The top collar includes at least one drain channel extendinglongitudinally downward into a top collar top surface. An interfacestructure is at least partially located longitudinally between the topcover and the top collar and prevents direct contact therebetween.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional side view of an example apparatusfor mitigating contamination of an optical device.

FIG. 2 is a schematic bottom view of the apparatus of FIG. 1.

FIG. 3 is a schematic cross-sectional side view of an example componentof the apparatus of FIG. 1.

FIG. 4 is a schematic bottom view of the component of FIG. 3.

FIG. 5 is a schematic cross-sectional side view of an example componentof the apparatus of FIG. 1.

FIG. 6 is a schematic bottom view of the component of FIG. 5.

FIG. 7 is a schematic cross-sectional side view of another examplecomponent of the apparatus of FIG. 1.

FIG. 8 is a schematic bottom view of the component of FIG. 7.

FIG. 9 is a schematic cross-sectional side view of the apparatus of FIG.1 in an example second example configuration.

FIG. 10 is a schematic cross-sectional side view of the apparatus ofFIG. 1 in an example third example configuration.

FIG. 11 is a schematic cross-sectional side view of an example componentof the apparatus of FIG. 1 in an example fourth example configuration.

FIG. 12 is a schematic bottom view of the component of FIG. 11 in theexample fourth example configuration.

DETAILED DESCRIPTION

This disclosure relates to a lens cover housing. Unless definedotherwise, all technical and scientific terms used herein have the samemeaning as is commonly understood by one of skill in the art to whichthe present disclosure pertains.

As an example, the housing includes a sidewall enclosing a lateraldimension of a protected volume. A bottom plate laterally spans thesidewall to enclose a bottom side and lower longitudinal dimension ofthe protected volume. The housing also includes a housing cap having atop cover, a top collar including a drain channel, and an interfacestructure at least partially located longitudinally between the topcover and the top collar and preventing direct contact therebetween. Forexample, the interface structure may include, or be at least partiallymade from, a compliant material that prevents contact forces associatedwith the housing from damping or suppressing vibrations from a structureinside the protected volume. The housing may at least partially sealwater and other contaminants from reaching the protected volume, mayfacilitate drainage of fluid, and may mitigate short-circuiting ofelectronics within the housing. The housing can be inexpensive tomanufacture and simple to assemble. The housing may also provide asimple and reliable way to electrically connect structures andcomponents within the protect volume and outside the housing, in asurrounding ambient space.

FIG. 1 depicts an example of an apparatus 100, shown here as an opticaldevice housing, for mitigating contamination of an optical device 102that resides within the housing. The apparatus 100 includes anopen-topped, closed-sided, and closed-bottomed housing cup 104 partiallydefining a protected volume 106 to enclose the optical device 102.

The housing cup 104 includes a sidewall 108 having longitudinally spacedtop and bottom sidewall rims 110 and 112. The “longitudinal” direction,as shown and described herein, is substantially parallel to longitudinalarrow “L”, which is substantially along the vertical direction, in theorientation of FIG. 1. The sidewall 108 encloses a lateral dimension ofthe protected volume 106. The “lateral” direction, as shown anddescribed herein, is substantially perpendicular to longitudinal arrow“L”, and is substantially along the horizontal direction, in theorientation of FIG. 1. Spatially relative terms, such as “under,”“below,” “lower,” “over,” “upper”, “up”, “down”, “top”, “bottom”, andthe like, may be used herein for ease of description to describe oneelement or feature's relationship to another element(s) or feature(s) asillustrated in the Figures. It will be understood that the spatiallyrelative terms can encompass different orientations of a device in useor operation, in addition to the orientation depicted in the figures.

A bottom plate 114 (such as a bottom cover), shown from the bottom inFIG. 2, laterally spans the bottom sidewall rim 112 to enclose a bottomside and lower longitudinal dimension of the protected volume 106. Thebottom side of the housing cup 104 (i.e., the bottom plate 114) mayinclude at least one of a via 218, a thru hole 220, and a PCB 216 for atleast one of mechanical and electrical communication longitudinallythrough the housing cup to provide a path for electrical communication(between an ambient space and the protected volume 106) longitudinallythrough the PCB 216. When present, the vias 218 and/or thru holes 220(each of which may be considered to be a form of a lumen, and any ofwhich may be provided to a PCB 216, panel, or other portion of thehousing) may be configured (such as through the use of epoxy potting orany other desired treatment) to prevent ingress of contaminants to theprotected volume 106 through the bottom plate 114. However, when thebottom side of the apparatus 100 is located within a larger housing ormounting structure, such protection of the vias 218 and/or thru holes220 may be selectively omitted. It is contemplated that the opticaldevice 102 could be directly attached to the PCB 216, when one ispresent. It is also contemplated that a transformer (not shown) could bedirectly or indirectly attached to the PCB 216, or to any other part ofthe apparatus 100, in any desired manner.

The bottom plate 114 or cover, regardless of whether or not a PCB 216forms at least a portion thereof, may include at least one thru hole 220extending therethrough to facilitate at least one of mechanical andelectrical communication between the ambient space surrounding theapparatus 100 and the protected volume 106. For example, the thru hole220 can enable electrical communication of signals (e.g., video imagedata) between the optical device 102 located inside the protected volume106 and a remote device (not shown) configured to receive and processsignals from the optical device. As another example, power and/or signal(similar to a speaker setup) could be provided to the optical device102, an ultrasonic transducer, and/or any other component of theapparatus 100 via the thru hole 220.

As shown in the example of the Figures, the bottom plate 114 may berecessed up into the housing cup 104 any desired amount, or in otherexamples may instead be flush with the bottommost edge of the housingcup 104.

With reference once again to FIG. 1, a housing cap 122 encloses a top(e.g., the top sidewall rim 110) of the housing cup 104 and thuspartially encloses an upper longitudinal dimension of the protectedvolume 106. That is, the housing cap 122 laterally spans the top of thehousing cup 104. The housing cap 122 may be attached laterally and/orlongitudinally to an outer sidewall 124 of the housing cup 104.

The housing cap 122 includes a top collar 126, shown in cross-sectionalside view in FIG. 3 and from the bottom in FIG. 4. The top collar 126has an open central aperture 428, shown in FIG. 4. The top collar 126laterally surrounds the top sidewall rim 110. In some examples, such asshown in the Figures, the top collar 126 may be threadably attached tothe sidewall 108 at the top sidewall rim 110. The top collar 126 mayinclude at least one drain channel 127 (one shown in FIGS. 1-10), whichextends longitudinally downward into the top collar 126 top surface andextends at least partially across the top collar 126 top surfacelaterally outward from the central aperture 428. Each drain channel 127may have any desired size and shape, though is shown as a flat-bottomed,constant cross-section void in the top collar 126 top surface in theFigures. Other examples of suitable configurations for the drain channel127 include, but are not limited to: tapering the cross-section of thevoid in any desired direction/orientation (e.g. gradually or abruptlyincreasing the “depth” of the drain channel 127 into the top collar 126top surface along the length of the drain channel 127 as the drainchannel 127 extends toward or away from the central aperture 428);providing a drain channel 127 which is wedge- or even triangle-shaped incross-section, with the topmost portion of the drain channel 127 (i.e.,the portion substantially flush with the top collar 126 top surface)being either wider or narrower than the bottommost portion of the void;and/or the drain channel 127 could have an at least partiallyrounded/cylindrical cross-section (e.g., round-bottomed) rather than therectilinear cross-section shown in the Figures. Likewise, the centralaperture 428 could have a particular configuration at least at theinterface with the drain channel 127. For example, the drain channel 127could meet the central aperture 428 at approximately a right angle, asshown in the Figures, or at least a portion of the sidewall of thecentral aperture 428 which interfaces with the drain channel 127 couldbe positively or negatively angled with respect to the top surface ofthe top collar 126. Each drain channel 127 may be radially aligned withthe central aperture 428 (or with the top collar 126 generally) toextend along a line passing through a radial center of the centralaperture 428 (or the top collar 126 generally), or could be offset asdesired to extend tangentially with respect to the radial center of thecentral aperture 428 (or the top collar 126 generally). The drainchannel 127 facilitates drainage of fluid from the central aperturetoward the outer surface of the housing cup 104. For example, suchdrainage via channel 127 may occur under gravitational influence whenthe apparatus 100 is mounted with the longitudinal direction beingsubstantially horizontal to a ground surface during use. The fluiddrainage through the drain channel 127 may be facilitated further byvibration or other movement of a vehicle or other object to which theapparatus 100 is attached.

The housing cap 122 also includes a top cover 130, shown incross-sectional side view in FIG. 5 and from the bottom in FIG. 6. Thetop cover 130 laterally spans the central aperture 428 of the top collar126. The top cover 130 laterally spans at least a portion of the topsidewall rim 110 to partially enclose a top side and upper longitudinaldimension of the protected volume 106. At least a portion of the topcover 130 may be at least one of optically transparent and opticallytranslucent, to allow an optical device 102 contained within theprotected volume 106 to make a desired amount of visual contact with theambient space around the apparatus 100.

The top cover 130 is laterally separated from the top sidewall rim 110by an insulation gap 132. The top collar 126 laterally spans theinsulation gap 132 to complete enclosure of the top side and thelongitudinal dimension of the protected volume 106, in combination withthe top cover 130 to collectively comprise the housing cap 122. The topcover 130 includes an ultrasonic transducer 534, shown in at least FIG.5 as a cylindrical annular ultrasonic transducer, such as, but notlimited to, such as piezoelectric cylinder SMC22D20H6412 (available fromSteiner & Martins, Inc. of Doral, Fla.), for selectively ultrasonicallyvibrating the top cover 130 to shed contaminants. The ultrasonictransducer 534 vibrates the top cover 130 longitudinally up and downand/or laterally left-to-right (in the orientation of FIG. 1) at veryhigh frequencies (e.g., between about 20 to about 400 kHz, for example,such as about 300 kHz) to mitigate contamination of the optical deviceby vibrating contaminants away from and off of the top cover 130. Inthis way, where the optical device 102 constitutes a camera, by removingcontaminants, such as water and dirt from the top cover, the field ofview for the camera may be cleared of obstructions.

The sidewall 108 is shown in cross-sectional side view in FIG. 7 andfrom the bottom in FIG. 8. As shown in FIG. 7, the sidewall 108 mayinclude a laterally thickened center segment 736 which protrudeslaterally into the protected volume 106. The center segment 736 may behelpful, for example, in laterally orienting an optical device 102and/or in longitudinally orienting the housing cap 122, or portionsthereof, with respect to other structures of the apparatus 100.

One or more longitudinal lumens 738 (each of which could act as a via218 and/or thru hole 220) could extend through the center segment 736,or through any other portion of the sidewall 108, to provide a path forcommunication (e.g., passage of a wire, not shown) between the top andbottom sidewall rims 110 and 112 within the protected volume 106. Forexample, electrical wires (not shown) could extend through one or morelongitudinal lumens 738 between the ultrasonic transducer 534 and atleast one via 218.

One or more alignment features 740 could be associated with the centersegment 736, or with any other portion of the sidewall 108, tofacilitate alignment and/or attachment of the apparatus 100 structuresrelative to each other. For example, as shown in FIGS. 7-8, at least onealignment feature 740 can be a protruding feature configured formale-to-female contact with at least one thru hole 220 of the bottomplate 114. The depicted alignment feature 740 may serve as, and/orreceive, a fastener (not shown) to attach the sidewall 108 to the bottomplate 114.

The sidewall 108, the bottom cover (e.g., bottom plate 114), the topcover 130, the top collar 126, and/or any other structures of theapparatus 100 may be made of a nonconductive material, such as, but notlimited to, acetal homopolymer resin, high density polyethylene,polytetrafluoroethylene, other plastic or polymer materials,nonconductive metals, or any combination thereof. For certain useenvironments, it may be desirable for at least one structure of theapparatus 100 to be made of a material which is not subject to unwantedultrasonic welding under vibratory forces induced by the ultrasonictransducer 534. It may also or instead be desirable for the apparatus100, or portions thereof, to be nonconductive to avoid electrical shortcircuits if, for example, the insulation of an electrical wire frays orwears over time under the vibratory load to expose the bare wire toadjacent and/or contacting structures of the apparatus 100.

As shown in the Figures, the sidewall 108 may be cylindrical, with thetop cover 130, the bottom cover (i.e., bottom plate 114), and the topcollar 126 all having substantially round or circular footprints, whenviewed in a longitudinal direction. (That is, when viewed from the topdirection looking down within the plane of the page, in FIG. 1.) Thedepicted configuration thus results in a substantially right cylindricalhousing, as shown, although any additional flanges (e.g., mountingflanges) or other features could be provided for a particular useenvironment. It is also contemplated that the apparatus 100, or portionsthereof, could have curved, linear, curvilinear, or any other desiredprofiles, for a particular use environment.

The optical device 102 may include at least one of a camera and a cameralens, and may be located wholly within the protected volume 106. Forexample, a barrel-shaped digital camera may serve as an optical device102 and provide digital images (e.g., video data) corresponding to afield of view of the camera through the lens cover 130 when mountedwithin the apparatus 100. The optical device 102 may be threadablyattached to the housing cup 104. An example of such attachment may befor the optical device 102 to be screwed into engagement with at leastone other surface of the housing cup 104. For example, the laterallythickened center segment 736 of the sidewall 108 may be threaded toreceive corresponding threads along the longitudinally extending sidesof the optical device 102. Such threadable engagement may provide aneasy means of attachment of the optical device 102 to the housing cup104 and stabilization between the two, as well as providing a way tocontrol the distance between the top of the optical device 102 and theunder (bottom) side of the top cover 130. The optical device 102 may bedirectly or indirectly fixed to a bottom side (e.g., the bottom plate114) of the housing cup 104, extend upward toward the top cover 130, andbe spaced longitudinally apart from the top cover 130.

An interface structure 142 may circumscribe the top cover 130 to suspendthe top cover 130 downwardly into the housing cup 104 from the topcollar 126, as shown in the first configuration of FIG. 1. The interfacestructure 142 prevents direct contact between the top cover 130 and thetop collar 126. In other words, the interface structure 142 may be atleast partially located longitudinally between the top cover 130 and thetop collar 126 and prevent direct contact therebetween. The interfacestructure 142 provides a compliant interface that mitigates, or reduces,transference or transmission of ultrasonic vibrations between the topcover 130 and the top collar 126. The interface structure 142 may bemade of flexible material such as, but not limited to, silicone rubber.

The interface structure 142 may be provided to the apparatus 100 as acompleted band-type structure and/or may be laid down between the topcover 130 and the top collar 126, in a caulk-type fashion, in a flowableform and permitted to cure in place, during manufacture of the apparatus100. The interface structure 142 also may prevent water and othercontaminants on the top surface of the housing cap 122 from penetratinginto the protected volume 106. The interface structure 142 thereforefacilitates vibration of the top cover 130 with respect to the sidewall108, and thus by absorbing the vibratory force can mitigate potentialmechanical damage to the structures of the apparatus 100 while removingcontaminants and fluids from the upper surface of the top cover 130.

It is contemplated that the material(s) used for the interface structure142 will have a relatively high mechanical compliance compared toadjacent portions of the apparatus 100. In this way, the interfacestructure operates to prevent contact forces associated with the topcollar 126 from damping or suppressing vibration generated by theultrasonic transducer 534. Thus, the housing structure does not dampenthe vibration of the ultrasonic transducer 534, thereby facilitatingremoval of fluid and/or other contaminants from the outer surface of thetop cover 130.

The previously mentioned threadable engagement between the variousportions of the apparatus 100 may also provide some degree ofadjustability to the compression of the interface structure 142 againstthe top cover 130 and/or the top collar 126, to provide a predeterminedbalance between sealing tightness and compliance properties of theinterface structure 142 in the completed apparatus 100. For example, andas is shown in the Figures, the housing cap 122 may at least partiallycontact, and rest upon (i.e., place weight upon) other structures of theapparatus 100. This example configuration is shown in at least FIGS. 1and 9-10 as a bottom rim of the ultrasonic transducer 534 beinglongitudinally adjacent to, and potentially contacting, at least aportion of the central segment 736 of the sidewall 108. That is, thecentral segment 736 of the sidewall 108 acts, in part, as an orientingfeature protruding laterally into the protected volume 106 from a sideof the housing cup 104 (while the central segment 736 is also providinga threadable engagement with the optical device 102). Alternately, arelatively small portion of the sidewall 108 or even a separatelyprovided structure (not shown) could be an orienting feature withoutengaging the optical device 102. Regardless of the preciseconfiguration, however, any provided orienting feature may selectivelycontact the housing cap 122 for orientation thereof with respect toother structures of the apparatus 100.

Therefore, when the top collar 126 is engaged (e.g., threadably engaged)with the sidewall 108 (e.g., the outer sidewall 124), the top cover 130,interface structure 142, and ultrasonic transducer 534 arelongitudinally “sandwiched” between the top collar 126 and the centralsegment 736 of the sidewall 108. Here, the interface structure 142mitigates transference of vibration from the ultrasonic transducer 534by allowing the top cover 130 to indirectly “push off” longitudinallyfrom the central segment 736, and deforming under that longitudinalforce to prevent transmission of the longitudinal force from the topcover 130 to the top collar 126.

A second example configuration of the interface structure 142, which canbe used in combination with any desired features of the firstconfiguration, is shown in FIG. 9. In FIG. 9, the top cover 130 hasoppositely facing downward and upward top cover surfaces 946 and 948,respectively, longitudinally spaced by a top cover rim 544 (labeled inFIG. 5). The interface structure 142 is a band which laterally encirclesthe top cover rim 544 of the top cover 130. Because the interfacestructure 142 of FIG. 9 has a “C”-shaped cross-section, as shown in thatFigure, the interface structure thus longitudinally spans the top coverrim 544 to directly longitudinally contact both the downward top coversurface 946 and the upward top cover surface 948, concurrently. Theinterface structure 142 may both laterally encircle and laterallycontact the top cover rim 544, also concurrently with the longitudinalcontact with the downward and upward top cover surfaces 946 and 948.This configuration of the interface structure 142, when present, mayassist with securely suspending the top cover 130 from the top collar126 and/or mitigate dampening the ultrasonic vibrations from theultrasonic transducer 534.

A third example configuration of the interface structure 142, which canbe used in combination with any desired features of the first and secondconfigurations, is shown in FIG. 10. In FIG. 10, the apparatus 100includes an insulation collar 1050 concurrently contacting a portion ofthe housing cap 122 longitudinally spaced from the interface structure142 and an inside sidewall 108 of the housing cup 104. As shown in FIG.10, the insulation collar 1050 acts to cushion and/or otherwise affectthe interface between the central segment 736 of the sidewall 108 andthe ultrasonic transducer 532. To that end, the insulation collar 1050may be at least partially resilient, and thus act on the bottom portionof the housing cap 122 in a manner similar to the interface structure142 on the top portion of the housing cap 122. The insulation collar1050 may also or instead be made of a friction-reducing material, suchas, but not limited to, polytetrafluoroethylene, to facilitate relativemovement between the housing cap 122 and the housing cup 104. For someuse environments of the apparatus 100, the insulation collar 1050 couldbe made of a material which is harder than the adjacent materials of thesidewall 108 and/or the housing cap 122, thus providing the transducer534 with a harder surface to push against than those of the sidewall 108and/or housing cap 122. The insulation collar 1050 may be at leastpartially made of a material with a higher melting temperature than thematerial of the sidewall 108 and/or the housing cap 122, to mitigatemelting or other adverse wear effects by the transducer 534 on otherportions of the apparatus 100.

It is contemplated that a reduced-friction liner ring 152 (shownschematically in FIG. 1) may be located at least one of laterally andlongitudinally between the housing cap 122 and the housing cup 104. Forexample, a liner ring 152 is shown in FIG. 1 as being sandwiched betweenthe interface structure 142 and a bottom edge of the top collar 126. Theliner ring 152, when present, could be made from polytetrafluoroethyleneor any other desired material or combination of materials (includingflowable lubricants), and may assist with facilitating relative movementbetween adjacent structures of the apparatus 100, such as by dampingvibratory motion of the top cover 130 from transference to the housingcup 104 or other structures of the apparatus 100.

Once the apparatus 100 has been assembled into a desirably fluid-tightunit as described above and shown in the Figures, the ultrasonictransducer 534 and/or the optical device 102 can be connected in anydesired manner to a controller, power source, computer, or any otherdevice in the ambient space (e.g., through electrical wires passedthrough the vias 218 and/or thru holes 220). The apparatus may bemounted to a supporting structure (not shown), such as through use ofthe alignment features 740. The ultrasonic transducer 534 is actuated asdesired, which could be at all times, only during operation of theoptical device 102, only during predetermined weather conditions, and/orin any other timing, sequence, or pattern. The ultrasonic vibrationswill vibrate the top cover 130 very rapidly to break up and expelcontaminants (including, but not limited to, particles and fluids) fromthe upward top cover surface 948. By removing such contaminants, forexample, the field of view for the optical device (e.g., a camera) 102can remain free and clear thereby producing clean images of objectswithin the field of view. While the vibrations are being produced by theultrasonic transducer 534, the interface structure 142 mitigatesdampening of such vibrations as well as serves to mechanically insulatethe interface between the top collar 126 and top cover 130. It iscontemplated that the interface structure 142, or any other portions ofthe apparatus 100 could be periodically inspected and either the entireapparatus 100 or portions thereof replaced as a predetermined amount ofundesirable wear occurs.

A fourth example configuration of the top collar 126, which can be usedin combination with any desired features of the first, second, and/orthird configurations, is shown in FIGS. 11-12. In FIGS. 11-12, aplurality of drain channels 127 are provided and are distributed aboutthe top collar top surface at a number of different radial orientations.(Four are shown here, but any desired number is contemplated.) Eachdrain channel 127 extends longitudinally downward into a top collar topsurface and extends at least partially across the top collar top surfacelaterally outward from the central aperture. The plurality of drainchannels 127 facilitate drainage of fluid from the central aperturetoward the outer surface of the housing cup 104, which may occur undergravitational influence and/or other forces that may occur when theapparatus 100 is mounted (e.g., to a vehicle) with the longitudinaldirection being substantially horizontal to a ground surface, duringuse.

The single drain channel 127 of the first example configuration may needto be carefully radially aligned during installation in a desiredorientation with respect to the housing cup 104 (e.g., located inapproximately a “six o'clock” position—substantially at a bottommostarea of the installed top collar 126) to ensure that gravity-influencedfluid drainage occurs as intended. In contrast, the radially spacedplurality of drain channels 127 of the fourth example configurationfacilitate installation of the top collar 126 in a number of differentradial orientations with respect to the housing cup 104 while stillproviding at least one of the plurality of drain channels in a generally“downward extending” orientation. Accordingly, the fourth exampleconfiguration permits the expenditure of less care and precision inassembly than in the first example configuration (which has only onepossible downward-facing drain channel 127 orientation) while stillresulting in at least one of the plurality of drain channels 127 beingin a “bottommost” or “six o'clock” orientation.

What have been disclosed herein are examples. It is, of course, notpossible to describe every conceivable combination of components ormethodologies, but one of ordinary skill in the art will recognize thatmany further combinations and permutations are possible. For instance,any structures or features described with reference to one embodiment orconfiguration could be provided, singly or in combination with otherstructures or features, to any other embodiment or configuration. Asanother example, the described structures and components could be madefrom any suitable material or combinations of materials. Any of thedescribed structures and components could be disposable or reusable asdesired for a particular use environment. Additionally, though certaincomponents described herein are shown as having specific geometricshapes, all structures of this disclosure may have any suitable shapes,sizes, configurations, relative relationships, cross-sectional areas, orany other physical characteristics as desirable for a particularapplication. For example, it is contemplated that the interfacestructure 142, as with any structure(s) of the apparatus 100, could besubstantially rotationally uniform symmetrical as shown (havingsubstantially the same cross-sectional shape/area all around acircumference thereof) or could instead include some irregularitieswhich provide different cross-sectional shapes/areas at different pointsalong the circumference. Accordingly, this disclosure is intended toembrace all such alterations, modifications, and variations that fallwithin the scope of this application, including the appended claims.

As used herein, the term “includes” means includes but not limited to,the term “including” means including but not limited to. Additionally,where the disclosure or claims recite “a,” “an,” “a first,” or “another”element, or the equivalent thereof, it should be interpreted to includeone or more than one such element, neither requiring nor excluding twoor more such elements.

What is claimed is:
 1. Apparatus, comprising: a housing having a top, aclosed side and a closed bottom, the housing adapted to enclose anoptical device; and a housing cap enclosing the top, the housing capincluding: a top collar having a top surface and an aperture through thetop surface, the top surface having a drain channel extending from theaperture at least partially across the top surface, a top cover spanningat least the aperture, and an interface structure attached between thetop collar and the top cover, the interface structure surrounding thetop cover and suspending the top cover into the housing from the topcollar and preventing direct contact between the top cover and the topcollar.
 2. The apparatus of claim 1, wherein the housing has an outersidewall, and the housing cap spans the top of the housing and isattached to the outer sidewall.
 3. The apparatus of claim 1, furthercomprising an ultrasonic transducer attached to the top cover andconfigured to ultrasonically vibrate the top cover to shed contaminants,the interface structure configured to mitigate a transference of contactforces between the top cover and the top collar.
 4. The apparatus ofclaim 1, wherein the drain channel is a flat-bottomed, constantcross-section void in the top surface.
 5. The apparatus of claim 1,wherein the top cover has opposite top and bottom surfaces and a rimtherebetween, and the interface structure encircles the rim and directlycontacts the opposite top and bottom surfaces.
 6. The apparatus of claim1, wherein the housing has an inside sidewall, a portion of the topcover is spaced from the interface structure, and the apparatus furthercomprises an insulation collar concurrently contacting the portion andthe inside sidewall.
 7. The apparatus of claim 1, wherein the bottom ofthe housing includes a via, a thru hole or a printed circuit board formechanical or electrical communication through the housing.
 8. Theapparatus of claim 1, wherein the top surface has multiple drainchannels distributed about the top surface at a number of differentradial orientations.
 9. The apparatus of claim 1, further comprising theoptical device fixed to the bottom of the housing, extending upwardtoward the top cover, and spaced apart from the top cover.
 10. Theapparatus of claim 1, further comprising a reduced-friction liner ringbetween the housing cap and the housing.
 11. The apparatus of claim 1,wherein the drain channel points to a center of the aperture.
 12. Anoptical device housing, comprising: a sidewall having top and bottomsidewall rims, the sidewall enclosing sides of a volume, and the topsidewall rim surrounding a top of the volume; a bottom plate spanningthe bottom sidewall rim to enclose a bottom of the volume; a housing capenclosing the top, the housing cap including: a top collar surroundingthe top sidewall rim, the top collar having a top surface and anaperture through the top surface, and the top surface having a drainchannel extending from the aperture at least partially across the topsurface, a top cover spanning at least the aperture, and an interfacestructure attached between the top cover and the top collar, theinterface structure surrounding the top cover and preventing directcontact between the top cover and the top collar, and the interfacestructure configured to mitigate a transference of contact forcesbetween the top cover and the top collar; and an ultrasonic transducerattached to the top cover and configured to ultrasonically vibrate thetop cover to shed contaminants.
 13. The optical device housing of claim12, wherein at least a portion of the top cover is optically transparentor optically translucent.
 14. The optical device housing of claim 12,wherein the bottom plate includes a thru hole extending therethrough tofacilitate mechanical or electrical communication between an ambientspace and the volume.
 15. The optical device housing of claim 12,wherein the bottom plate includes a via, a thru hole or a printedcircuit board for mechanical or electrical communication longitudinallythrough the sidewall.
 16. The optical device housing of claim 12,wherein the drain channel is a flat-bottomed, constant cross-sectionvoid in the top surface.
 17. The optical device housing of claim 12,wherein the drain channel points to a center of the aperture.
 18. Theoptical device housing of claim 12, wherein the top cover has oppositetop and bottom surfaces and a top cover rim therebetween, and theinterface structure encircles the top cover rim and directly contactsthe opposite top and bottom surfaces.
 19. The optical device housing ofclaim 12, wherein the top surface has multiple drain channelsdistributed about the top surface at a number of different radialorientations.